Liposuction concerns the removal of fat (adipose tissue) from under the skin. Usually fat is removed from the deep layer of subcutaneous tissue found in the hypodermis layer of the skin. Fat may be removed from the superficial layer of subcutaneous fat, but this is more difficult because that layer is denser than the deep layer and is tightly packed with nerves and blood vessels. Removing fat from the superficial layer risks damage to functional components of the skin, which can result in visible permanent irregularities, discolorations, and possibly skin necrosis.
In conventional liposuction procedures, a wetting solution or subcutaneous infiltration is used to promote ease of fat aspiration. Components of subcutaneous infiltrate include a base fluid of normal saline or lacerated Ringer's solution. Epinephrine is often added to this solution and lidocaine and/or bupivacaine may also be used for analgesia. Sometimes, gentamicin is added for infection prophylaxis and hyaluronidase to aid in lipolysis. Lidocaine toxicity must be avoided when carrying out the liposuction procedure in the traditional manner.
The sequence of filtration is normally such that infusion is generally done sequentially for each body area treated so as to minimise the overall fluid and pharmacologic load. It is normal to have a 10 to 20 minute latency period prior to aspiration to allow for epinephrine to have a maximal vasoconstrictive effect. This process can make the overall procedure unnecessarily time consuming.
Care must also be taken in conventional liposuction procedures to avoid perforation of the underlying fascia, peritoneum, and abdominal structures. Furthermore, the patient's fluid balance must be closely monitored when carrying out conventional liposuction. Blood loss caused when performing conventional liposuction may also be a major concern. There is a high risk of bleeding during and after the procedure. Medication to treat bleeding may be required.
U.S. Pat. No. 5,295,955 proposes using radiofrequency electromagnetic energy in combination with a conventional liposuction arrangement to heat fat at the treatment site so that it would soften and be easier to remove. However, it is essential to provide a polar liquid within the treatment site for the heating to be effective. Presence of this liquid increases patient discomfort. Moreover, it may be difficult to control excess heat generation which may cause undesirable collateral tissue damage.
U.S. Past. No. 6,920,883 proposes targeting electrical energy at a treatment region by providing active and return electrodes in close proximity to targeted tissue. An electrically conductive fluid is located between the electrodes to define a high frequency current path through targeted tissue. Current flow causes heating, softening or ablation of the targeted tissue.
U.S. Pat. No. 7,112,200 discloses a power-assisted liposuction device which is arranged to perform electro-cauterization. The liposuction device comprises an inner and outer cannula having active and return electrodes mounted thereon respectively to define a high frequency current path there-between.